Y hccaig abtb wilj



H. McCAlG AND W. C. STEVENSON.

APPARATUS FOR PREHEATING UNCALCINED MATERIAL PRIOR TO ITS ENTRY INTO THE KILN.

APPLICATION EILEII APR.23. 1917.

1,308,088. mmm May (a, 10m.

1 IE 4 j M;

"I ,I IWIII/IJIH W/H/M IA'VENTORS.

A TTORNE Y.

hrlzi sg eve/won snares raniv r enrren.

MCCATG MED WIIL'JFREZD UUETIS STEVENSON, 01E CEMENT, CALIFORNIA.

iron riannnarrn'e nn'cancrnnn runrnnrar. rnron ro rrs nn'rnr inro rrrn nrnn.

incense.

Specification of Letters Patent.-

Patented May @1919.

Application filed April 23, 1917. Serial No. 16%,0t35.

To (ZZZ whom it mag concern.

Be it known that we, HARRY Mc-CAIG and iiinrnnnCun'rrs STEVENSON, citizens of the United States, residing at Cement, 1n the county of Solano, State of California, have invented certain new and useful Improvements in Apparatus for Preheating Uncalcined Material lPrior to its Entry into the Kiln; and we do declare the following to be a full clear, and exact descriptlon of the same, reference being had to the accom: panying drawings, and to the characters of reference marked thereon, which form a part of this application. I

This invention relates to improvements in calcining apparatus. The object of the invention is to provide an apparatus for utilizing the heat from stack gases issuing from rotary kilns to preheat the uncalcined material prior to its admission to the k111i. Our improved apparatus performs both the function of preheating the uncalcined material and incidentally reducing the temperature of the stackgases. The advantages of both functions will be apparent to those skilled in the art.

A further object of the invention is to produce a simple and inexpensive device and yet one which will be exceedingly effective for the purposes for which it is designed.

These objects we accomplish by means of such structure and relative arrangement of parts as will fully appear by a perusal of the following specification and claim.

In the drawings similar characters of reference indicate corresponding parts in the several views.

Figure 1 is a vertical section of the apparatus by means of which we carry out our improved method.

2 is a sectional view taken centrally through our improved preheating bin.

Referring now more particularly to the characters of reference on the drawings the numeral 1 designates the upper end of the rotary kiln delivering into which is the delivery feed pipe 2 to which is supplied the uncalcined material in a manner as will of this retort 5. Located within the retort 5 is a material bin 6 which is substantially cone shaped ateach end. An inlet opening 7 is provided at the upper end of the bin 6 and an outlet opening 8 is provided at the lower end which discharges into a feed gate member 9 which in turn delivers to the inlet pipe 2 and hence into the kiln l. The bin 6 completely fillsbetween the side walls of the preheating retort 5 and is spaced from the ends thereof to form end chambers 5 and 5*. These chambers are placed in communication with each other byineans of vertical passage ways or pipes 5 which communicate from the chamber 5 to the chamber 5 and pass through the bin. 6. The uncalcined material 10 when filled into the bin 6 completely surrounds all of these vertical pipes 5. The stack gases pass first from the kiln 1 through the base 3 thence to the stack l. From the stack t they pass into the chamber 5% thence through the vertical pipes 5 and into the chamber 5" and then from the chamber 5 back into the stack l.

The uncalcined material is therefore held in the presence of these heated gases for a considerable period, which not only causes the material to become heated but incidentally reduces the temperature of the stack gases' The advantages of this are obvious. Thus the uncalcined material is heated to a considerable degree prior to its entry into -the kiln 1, which causes the action within the kiln-to be much quicker and more effective than if such material had not been so preheated.

We are well aware that prior-to our invention heat from the stack gases from rotary kilns has been utilized forvarious purposes but we are not aware that the same has been utilized for the purpose of raising the temperature of the uncalcined material as we aim to do by employing our improved method as herein set forth.

From the foregoing description it will be readily seen that we have produced such'a device as substantially fulfils the object of the invention as set forth herein.

While this specification sets forth in detail the present and preferred construction of the device, still in practice such deviations from such detail may be resorted to as do not form a departure fromthe spirit of the invention as defined by the appended claim.-

\ ranged within the enlarged portion having a' stack base into which the gases from the kiln discharge, a' stack leading from the base, said stack having an enlarged portion above and adjacent to the base, a bin ar its top and bottom substantially cone-shaped and, spaced from the topand bottom walls of the enlarged portion of the stack, an inlet into the top of the bin, an outlet therefrom at the lower end delivering to thekiln and having a feed gate interposed therein, and

vertical flues through the bin communicating with the u per and lower portions of the enlarged portion of the stack, whereby the heated gases from the kiln during their passage up the stack will completely surround the uncalcined material in the bin and thoroughly heat the same prior to its entry into the kiln.

In testimony whereof, we aflix our signatures, in the presence of two witnesses.

HARRY MGCAIG; WILFBED CURTIS STEVENSON. Witnesses:

JAY HENRY, GEORGE J. RAYMOND. 

